This invention relates to luminaire construction and in particular to a novel air blade design for use in air handling luminaires having multipurpose capabilities. While the invention is described in detail with respect to a particular luminaire or lighting fixture design, those skilled in the art will recognize the wider applicability of the air blade construction disclosed.
Buildings of various types commonly utilize fluorescent lighting fixtures or luminaires, designations used interchangeably in this specification, for various functions. Thus, the architectural specifications for lighting installation may call out a non-air handling unit for one particular area, while other areas may require a fixture capable of air supply, air return, heat transfer or combinations of these functions. In order to meet this multi-application demand, the lighting fixture structure is arranged so that it can be adapted for any of the above uses by relatively simple modification. In general, the fixture modifications are designed so that they may be accomplished by field personnel at the particular job site. Fixture manufacturers thus are able to build and store single fixture models which are adaptable to a variety of uses.
A number of luminaire designs are known in the art which are capable of multipurpose uses. In one commercially successful prior art design, the lighting fixture includes a peripheral lip defining a cavity. The lip has a top wall having a plurality of openings in it. The openings are intended to receive a connector from an appropriate air supply when the fixture is used in its air supply mode. Because the unit is manufactured initially as a non-air handling unit, the openings are closed by connection knockouts. That is, the openings as manufactured, have metal portions closing them, the metal portions being removed when use of the openings is required. An air blade also is provided with the fixture. In this particular prior art design, the air blade was mounted in the cavity defined by the lip so as to give a horizontal distribution to air passing through the cavity. Vertical air distribution required the removal of the air blade from the cavity. While this form of fixture works well for its intended purpose, the removal of the knockouts, and the necessary removal of the air blade when vertical air distribution is desired, are relatively time consuming and expensive on site installation procedures.
In order to eliminate the requirement for knockouts as a feature of the lighting fixture structure, various adjustable air blades have been designed which are movable between a first position which closes the openings in the lip of the fixture and at least two other positions corresponding to blade setting for horizontal and vertical air distributions. While this type of design again works well for its intended purpose, the air blade construction is relatively expensive from the manufacturers standpoint.
Our invention resolves these prior art difficulties by providing an air blade construction which may be used to close the air admitting openings in the lip of the fixture, which may be positioned easily to provide either horizontal or vertical air distribution, and which is more economical to manufacture than other known prior art air blade designs.
One of the objects of this invention is to provide a simplified air blade construction for utilization in a multipurpose luminaire.
Another object of this invention is to provide a low cost air blade design.
Yet another object of this invention is to provide an air blade design in which individual sections of an overall air blade may be moved independently of other sections of the overall air blade design.
Other objects of this invention will be apparent to those skilled in the art in light of the following description and accompanying drawings.